It has long been the practice to dispose of garbage, refuse, trash and like matter in landfills located in areas designated specifically for that purpose. More recently, the availability of areas for landfills has diminished quite drastically, presenting acute problems in the disposal of garbage and like matter. In addition government regulations in most parts of the United States now require that new landfills be constructed with liners, membranes, films or other covering systems that isolate and protect the soil and ground water beneath bottom of the landfill from contamination by the refuse and its associated leachate. A primary concern of landfill operation is the preservation of the integrity of such liners or covering systems. In an effort to maximize the volume capacity of an active landfill several methods of compaction of the refuse have been tried.
The conventional method of compacting active landfills is through the use of a static compactor as described in U.S. Pat. No. 3,614,867 (Nieman). Static compaction is accomplished by the repeated rolling of a heavy wheeled vehicle having smooth, spiked or cleated rollers to break down and compact a layer of refuse. However, such wheeled static compactors are limited in the degree of compaction obtained by the weight of the wheeled vehicle and/or spiked roller. Compaction of refuse below the surface of a landfill using complicated machinery has been described in U.S. Pat. Nos. 3,466,026 (Fikse) and 3,511,056 (Jones et al.). Another below ground method of compacting refuse is described in U.S. Pat. No. 3,835,652 (Hignite), where a plurality of large vertical holes are drilled into firm soil. Refuse is then dumped into the holes and then hammered into a tight slug, before eventually being covered with a soil cap.
Unrelated to refuse disposal or the maintenance of active landfills, is the known general method of compacting earth in preparation for placing structures, such as buildings, roads, railways and the like. U.S. Pat. No. 1,650,827 (Friz) describes compaction of earth by successive vertical drops of a weighted hammer. Similar methods of compacting earth in preparation for the eventual construction of roadways, buildings and other structures has been accomplished using the weighted hammer method. Such techniques are described in two articles, Lukas, R. G. (1986), Dynamic Compaction For Highway Construction, Vol. 1; Design and Construction Guidelines, U.S. Department of Transportation and Welsh, J. P. (1983), Dynamic Deep Compaction of Sanitary Landfill To Support Super Highway, Proc. 8th European Conference on SMFE, Helsinki, 1, 319-321.
Although the need to increase the capacity of the active landfills has been recognized, the art has not described or suggested a method to enhance the volume of an above ground and/or incised active landfill using a dynamic compaction method while preserving the integrity of the liner or covering system.